1. The problem statement, all variables and given/known data I am trying to find the equation for lambda four for mechanical harmonics. 2. Relevant equations I know that lambda1=2L, lambda2=L, lambda3=2L/3, but neither google nor my textbook have the equation for lambda4! 3. The attempt at a solution I have searched my physics textbook, class notes, and google for this and have come up with absolutely nothing. Can anyone please assist? I would greatly appreciate it! Thank you!